I always hear the same thing whenever someone brings up Assault suit balance or that they lack a role. "Their role is to assault locations and kill people. They can do that so they have a role." That isn't a role; that is just using their name in a sentence and describing them doing something that anyone can do (kill people). Would be like saying "the point of the Logistics is to do logistics and kill people so they have a role."

With the addition of cloaks, Scouts now have something that they can do better than anyone else. They can hide, flank, and escape better than any other suit because of the ease of fitting cloaks. Neat. So this is the current status:

Scout: Cloak. Assassin, flanking, escaping, being invisible. Their bonuses help them fit a cloak, evade capture, find people, or steal objectives. It all fits into being sneaky.
Sentinel: Tanky; point defense, pushing. Their bonuses make them far more resistant to splash weapons, useful considering their slow speed, and more resistant against specific weaponry (the weapon of choice against their hated enemy and a smaller resistance against their ally's weapon).
Commando: Weapon versatility, high defenses, lots and lots of damage. Bonus allows them to reload faster and deal more damage with their chosen weapon type.
Logistics: Support; they are now flat out the best for using equipment. Blanket bonus helps to fit equipment and racial bonus makes their racial equipment better.
Assaults: What do they do better than the other suits? (Honest question) Blanket bonus helps them fit light weapon and sidearm and either help them in prolonged engagement (Amarr-Minmatar), close range (Gallente), or reload faster (Caldari). There is a distinct lack of consistency between the racial assault bonuses compared to the racial bonuses of the other suit types.

All other non-Assault suits I can look at and immediately see where they are supposed to shine. Assaults don't really seem to have that. They have nothing where they can just proclaim "I am the best at this thing; I do it better than anyone else." Before cloaks, Scouts were kind of in the same boat. They were harder to find but really any suit could flank and kill people. Now with cloaks, Scouts can do it better than the other guys.

Of course, I am not even sure what Assaults would get or do in order to make their role significant beyond "you are a medium suit that kills people."